Lopingian
Lopingian is the third of the three epoches of the Permian period. The Lopingian climate was hot and arid. This epoch saw one the largest deserts of all time, in the middle of the supercontinent Pangaea. Monsoons most likely prevailed in the coasts or a little further inland. There were probably fewer glaciers than in the previous epoch. By the beginning of the epoch saw the extinction of the dominating Dinocephalians therapsids and many remaining pelycosaurs. They were replaced by smaller therapsids, the Gorgonopsians, Therocephalians, and the cynodonts. Other animals, such as the Pareiasaurs replaced the herbivorous dinocephalians, while many animals such as tetrapods, insects, etc., were abundant on land as small to medium sized creatures. In the seas, life was abundant. This all came to a sudden halt, when an unknown mass extinction ended Lopingian, and of course the Paleozoic Era. This was the Permian-Triassic extinction event, the greatest mass extinction of the history of earth. The Cretaceous–Tertiary extinction event pales on comparison with this event. About 90% of all species in the sea died out, as did over 75% of all land species. By the time the extinction stopped, life on land and sea were virtually empty, although survivors have come to fill the empty void. The era of Paleozoic was over, and the era of Mesozoic era had begun. The epoch is followed by Early Triassic Epoch. The Lopingian epoch constitutes the last subdivision of the Permian, following the Guadalupian. It is divided into two unequal epochs, the long Wuchiapingian and the short (only about 2 million years) Changhsingian. The Lopingian, Wuchiapingian and Changhsingian are named after Chinese localities where fossils and rock strata of this age occur in a good and mostly unbroken series. As part of the current revision of Permian stratigraphy, "Lopingian" and "Guadalupian" have replaced earlier terms like "Upper Permian", "Zechstein", "Tartarian", and "Dzulfinan" in international usage (although the latter three terms are still applied locally). The Lopingian epoch lasted about as long as the preceding Guadalupian, approximately 9 million years. This was a period of great stress for eco-systems, as the climate continued to dry and the single large continent of Pangea did not provide much room for diversity (the more isolated islands and continents, the more species). Throughout the Permian period the numbers of invertebrate species tends to decrease. At the end of the Lopingian there is a period of enormous vulcanism (in what is now Siberia), which further stresses ecosystems by introducing acid rain into the atmosphere. Finally, at the end of the period there appears to have been either a tremendous period of vulcanism or an extraterrestrial impact (possibly a comet or giant asteroid similar to the one that killed the dinosaurs), as 95% of species of living beings suddenly die out within a very short period. The Paleozoic era comes to an end and new species inherit the globe. Lopingian Tetrapods In the dry late Permian environment many types of synapsids and reptiles flourished. The giant eotitanosuchids and dinocephalians of the Middle Permian had vanished, but the big pareiasaurs were still around, sharing the world with various types of more advanced therapsids that had likewise survived, including the large gorgonopsians like Gorgonops the small to medium-sized therocephalians, the newly evolved and very mammal-like cynodonts like Procynosuchus, and an astonishing diversity of herbivorous dicynodonts. A great many small insectivorous lizard-like diapsid reptiles, like Paliguana, inhabited the landscape, most of which, curiously, had hind-legs much longer than their forelimbs (clearly an adaptation to bipedal locomotion, like the frill-necked lizard of Australia today). Finally, the basal tetrapods, although reduced in numbers, were nevertheless present and included animals of large size. The aquatic rhinesuchid and capitosaurian temnospondyls were clearly the successors of the Middle Permian melosaurs and early Permian eryopids, both of which they resembled closely in size, appearance, and no doubt habits as well. As the biggest animals around, the fearsome looking, but herbivorous, pareiasaurs were nevertheless not free of danger. They had outlasted the carnivorous anteosaurian dinocephalians, but now the previously small and insignificant gorgonopsians had evolved to large forms (up to the size of a modern lion or bear) to take their place. These animals, the equivalent of the sabre-toothed cat of the Cenozoic era, used their enormous canines to bring down the ox- to rhino sized pareiasaurs. Gorgonopsians and pareiasaurs may even have formed a "co-adaptive pair" (like the Smilodon-mammoth 'relationship' of the Pleistocene); the gorgonopsians evolved in larger, more robust and larger fanged forms (for example Dinogorgon and Inostrancevia) whereas their pareiasaur prey become more armoured (for example Pareiasaurus and Scutosaurus). Both groups became simultaneously extinct and the end of the Permian. Category:Geologic Ages Category:Permian